Resilient Design and Operation of Complex Cyber-Physical Systems

Context: Cyber-Physical Systems encompass all modern engineered systems, including smart transit, smart emergency response, smart grid. The big issue in these systems is the construction and operation of the system in a safe and efficient manner. We strive to follow the methodology of building these systems using a component-based design whenever possible. The guiding principles of component-based design are interfaces with well defined execution models, compositional semantics and analysis. However, there are a number of challenges that have to be resolved (a) performance management, (b) modularization and adaptation of the design as the requirements and environment changes, (c) safe and secure design of the system itself and ensuring that new design and component additions can be compositionally analyzed and operated during the life cycle of the system, (d) fault diagnostics and failure isolation to detect and triage problems onlines and (e) reconfiguration and recovery to dynamically adapt to failures and environmental changes to ensure the safe completion of mission tasks.

Component based design Our work in the area of system integration and middleware for cyber physical systems has spanned over a decade. Together with Prof. Gabor Karsai at the Institute for Software Integrated Systems and Prof. Aniruddha Gokhale and Prof. Doug Schmidt at the Distributed Object Computing Group at Vanderbilt University, we have been working on CORBA, DDS, and system performance modeling. One of the key contributions we have made is the work on ARINC-653 Component Model (ACM), which combines the principle of spatial and temporal partitioning with the interaction patterns derived from the CORBA Component Model (CCM). The main extension over the the CCM are as follows: (a) The synchronous (call-return) and asynchronous (publish-subscribe) interfaces can be equipped with monitors that validate pre- and post-conditions over data that is passed on the respective interface, (b) The relevant portions of the state of the component can also be observed via a dedicated state interface, enabling the monitoring of invariants, (c) The resource usage of the component can be monitored via a resource interface that component uses for allocating and releasing resources and (d) The timing of component execution can be observed via control interface such that instance execution time violations can be detected. Given these extensions, component-level monitoring can be accomplished that evaluates pre- and post-conditions on method invocations, verifies the state invariants, tracks the resource usage, and monitors the timing behavior of the component.

This work was eventually extended and incorporated into DREMS (Distributed Real-Time Embedded Managed Systems) component model for networked CPS. It prescribed a single threaded execution model for components, which helped avoid synchronization primitives that often lead to non-analyzable code and can cause run-time deadlocks and race conditions. One of the key innovations in DREMS was development of fine-grained privileges for controlling access to system services. As part of this effort we developed a novel Multi-Level Security (MLS) information sharing policy across distributed architectures. Recently this model has been extended for a decentralized architecture for smart grid within the framework called Resilient Information Architecture Platform for Smart Grid.

Fault detection and diagnostics: Building on this foundation, we have been also working to develop mechanisms for anomaly detection, fault source isolation and recovery of the systems. In particular, we use a discrete event model that captures the causal and temporal relationships between failure modes (causes) and discrepancies (effects) in a system, thereby modeling the failure cascades while taking into account propagation constraints imposed by operating modes, protection elements, and timing delays. This formalism is called Temporal Causal Diagram (TCD) and can model the effects of faults and protection mechanisms as well as incorporate fine-grain, physics-based diagnostics into an integrated, system-level diagnostics scheme. The uniqueness of the approach is that it does not involve complex real-time computations involving high-fidelity models, but performs reasoning using efficient graph algorithms based on the observation of various anomalies in the system. TCD is based on prior work on Timed Failure Propagation Graphs (TFPG). When fine-grain results are needed and computing resources and time are available, the diagnostic hypotheses can be refined with the help of the physics-based diagnostics. Finally, we use both data-driven approaches like LSTM and graphical neural networks and the TCD models to prognosticate the effect of failures.

One of the key benefits of our approach of formalized component based construction is that we can generate a Timed Failure Propagation Graph (TFPG) from software assemblies and then use it in runtime to isolate faulty components. This is possible because the data and behavioral dependencies (and hence the fault propagation) across the assembly of software components can be deduced from the well-defined and restricted set of interaction patterns supported by the framework. We have also shown that fault containment techniques could be used to provide the primary protection from propagating failures into the high-criticality components and overall protect the system health management framework as well.

Recovery: We have also research mechanisms to recover from component failures by either reinstalling the components automatically or recovering the system functionality with alternative compositions in case of device and hardware failures. The key idea is to encode and use the design space of the cyber-physical system. This design space presents the state of an entire platform. It includes information about different resources available, well known faults, system goals, objectives and corresponding functionalities that help achieve different system goals, components that provide aforementioned functionalities, and possible different ways in which these components can be deployed and configured (this is captured using a domain specific language).

The design space can expand or shrink depending on addition or removal of related entities. A configuration point represents a valid configuration which includes information about a specific deployment scenario given a set of component instances and physical nodes on which these component instances can be deployed. A change in the state of a platform is represented by transition from one configuration point to another in the same design space. An initial configuration point represents the initial state, whereas the current configuration point represents the current state of a platform. Configuration points and their transition are critical for the self-reconfiguration mechanism that I have developed. The key idea is to reconfigure by migrating/transitioning from a faulty configuration point to a new configuration point by solving the problem using efficient SMT solvers. Additionally, if we have past information about component failures, we can reconfigure components to maximize the likelihood that the mission will succeed.

Publications in this area

  1. A. Chhokra, C. Barreto, A. Dubey, G. Karsai, and X. Koutsoukos, Power-Attack: A comprehensive tool-chain for modeling and simulating attacks in power systems, in 9th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek, 2021.
  2. H. M. Mustafa, M. Bariya, K. S. Sajan, A. Chhokra, A. Srivastava, A. Dubey, A. von Meier, and G. Biswas, RT-METER: A Real-Time, Multi-Layer Cyber–Power Testbed for Resiliency Analysis, in 9th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek, 2021.
  3. Z. Kang, Y. D. Barve, S. Bao, A. Dubey, and A. Gokhale, Poster Abstract: Configuration Tuning for Distributed IoT Message Systems Using Deep Reinforcement Learning, in International Conference on Internet-of-Things Design and Implementation (IoTDI), 2021.
  4. S. Basak, S. Sengupta, S.-J. Wen, and A. Dubey, Spatio-temporal AI inference engine for estimating hard disk reliability, Pervasive and Mobile Computing, vol. 70, p. 101283, 2021.
  5. K. Sajan, M. Bariya, S. Basak, A. K. Srivastava, A. Dubey, A. von Meier, and G. Biswas, Realistic Synchrophasor Data Generation for Anomaly Detection and Event Classification, in 8th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek, 2020.
  6. T. Bapty, A. Dubey, and J. Sztipanovits, Cyber-Physical Vulnerability Analysis of IoT Applications Using Multi-Modeling, in Modeling and Design of Secure Internet of Things, John Wiley & Sons, Ltd, 2020, pp. 161–184.
  7. H. Tu, Y. Du, H. Yu, A. Dubey, S. Lukic, and G. Karsai, Resilient Information Architecture Platform for the Smart Grid: A Novel Open-Source Platform for Microgrid Control, IEEE Transactions on Industrial Electronics, vol. 67, no. 11, pp. 9393–9404, 2020.
  8. S. Nannapaneni, S. Mahadevan, A. Dubey, and Y.-T. T. Lee, Online monitoring and control of a cyber-physical manufacturing process under uncertainty, Journal of Intelligent Manufacturing, pp. 1–16, 2020.
  9. Z. Kang, R. Canady, A. Dubey, A. Gokhale, S. Shekhar, and M. Sedlacek, A Study of Publish/Subscribe Middleware Under Different IoT Traffic Conditions, in Proceedings of the 7th Workshop on Middleware and Applications for the Internet of Things, M4IoT@Middleware, 2020.
  10. B. Potteiger, F. Cai, A. Dubey, X. Koutsoukos, and Z. Zhang, Security in Mixed Time and Event Triggered Cyber-Physical Systems using Moving Target Defense, in 2020 IEEE 23rd International Symposium on Real-Time Distributed Computing (ISORC), 2020, pp. 89–97.
  11. P. Ghosh, S. Eisele, A. Dubey, M. Metelko, I. Madari, P. Volgyesi, and G. Karsai, Designing a decentralized fault-tolerant software framework for smart grids and its applications, Journal of Systems Architecture, vol. 109, p. 101759, 2020.
  12. A. Bhattacharjee, A. D. Chhokra, H. Sun, S. Shekhar, A. Gokhale, G. Karsai, and A. Dubey, Deep-Edge: An Efficient Framework for Deep Learning Model Update on Heterogeneous Edge, in 2020 IEEE 4th International Conference on Fog and Edge Computing (ICFEC), 2020.
  13. A. Chhokra, N. Mahadevan, A. Dubey, and G. Karsa, Qualitative fault modeling in safety critical Cyber Physical Systems, in 12th System Analysis and Modelling Conference, 2020.
  14. S. Eisele, T. Eghtesad, N. Troutman, A. Laszka, and A. Dubey, Mechanisms for Outsourcing Computation via a Decentralized Market, in 14TH ACM International Conference on Distributed and Event Based Systems, 2020.
  15. S. Eisele, C. Barreto, A. Dubey, X. Koutsoukos, T. Eghtesad, A. Laszka, and A. Mavridou, Blockchains for Transactive Energy Systems: Opportunities, Challenges, and Approaches, IEEE Computer, 2020.
  16. S. Shekhar, A. Chhokra, H. Sun, A. Gokhale, A. Dubey, X. Koutsoukos, and G. Karsai, URMILA: Dynamically Trading-off Fog and Edge Resources for Performance and Mobility-Aware IoT Services, Journal of Systems Architecture, 2020.
  17. S. Hasan, A. Dubey, G. Karsai, and X. Koutsoukos, A game-theoretic approach for power systems defense against dynamic cyber-attacks, International Journal of Electrical Power & Energy Systems, vol. 115, 2020.
  18. A. Chhokra, S. Hasan, A. Dubey, and G. Karsai, A Binary Decision Diagram Based Cascade Prognostics Scheme For Power Systems, in 2020 American control conference, 2020.
  19. A. Dubey, G. Karsai, P. Völgyesi, M. Metelko, I. Madari, H. Tu, Y. Du, and S. Lukic, Device Access Abstractions for Resilient Information Architecture Platform for Smart Grid, Embedded Systems Letters, vol. 11, no. 2, pp. 34–37, 2019.
  20. A. Laszka, A. Mavridou, S. Eisele, E. Statchtiari, and A. Dubey, VeriSolid for TRANSAX: Correct-by-Design Ethereum Smart Contracts for Energy Trading, in First International Summer School on Security and Privacy for Blockchains and Distributed Ledger Technologies, BDLT 2019, Vienna, Austria, 2019.
  21. A. Mavridou, A. Laszka, E. Stachtiari, and A. Dubey, VeriSolid: Correct-by-Design Smart Contracts for Ethereum, in Financial Cryptography and Data Security - 23rd International Conference, FC 2019, Frigate Bay, St. Kitts and Nevis, Revised Selected Papers, 2019, pp. 446–465.
  22. S. Shekhar, A. Chhokra, H. Sun, A. Gokhale, A. Dubey, and X. D. Koutsoukos, Supporting fog/edge-based cognitive assistance IoT services for the visually impaired: poster abstract, in Proceedings of the International Conference on Internet of Things Design and Implementation, IoTDI 2019, Montreal, QC, Canada, 2019, pp. 275–276.
  23. P. Ghosh, S. Eisele, A. Dubey, M. Metelko, I. Madari, P. Völgyesi, and G. Karsai, On the Design of Fault-Tolerance in a Decentralized Software Platform for Power Systems, in IEEE 22nd International Symposium on Real-Time Distributed Computing, ISORC 2019, Valencia, Spain, 2019, pp. 52–60.
  24. Y. Zhang, S. Eisele, A. Dubey, A. Laszka, and A. K. Srivastava, Cyber-Physical Simulation Platform for Security Assessment of Transactive Energy Systems, in 7th Workshop on Modeling and Simulation of Cyber-Physical Energy Systems, MSCPES@CPSIoTWeek 2019, Montreal, QC, Canada, 2019, pp. 1–6.
  25. T. Krentz, A. Dubey, and G. Karsai, Short Paper: Towards An Edge-Located Time-Series Database, in IEEE 22nd International Symposium on Real-Time Distributed Computing, ISORC 2019, Valencia, Spain, May 7-9, 2019, 2019, pp. 151–154.
  26. G. Pettet, S. Sahoo, and A. Dubey, Towards an Adaptive Multi-Modal Traffic Analytics Framework at the Edge, in IEEE International Conference on Pervasive Computing and Communications Workshops, PerCom Workshops 2019, Kyoto, Japan, March 11-15, 2019, 2019, pp. 511–516.
  27. J. P. Talusan, F. Tiausas, K. Yasumoto, M. Wilbur, G. Pettet, A. Dubey, and S. Bhattacharjee, Smart Transportation Delay and Resiliency Testbed Based on Information Flow of Things Middleware, in IEEE International Conference on Smart Computing, SMARTCOMP 2019, Washington, DC, USA, June 12-15, 2019, 2019, pp. 13–18.
  28. M. Wilbur, A. Dubey, B. Leão, and S. Bhattacharjee, A Decentralized Approach for Real Time Anomaly Detection in Transportation Networks, in IEEE International Conference on Smart Computing, SMARTCOMP 2019, Washington, DC, USA, 2019, pp. 274–282.
  29. A. Dubey, W. Emfinger, A. Gokhale, P. Kumar, D. McDermet, T. Bapty, and G. Karsai, Enabling Strong Isolation for Distributed Real-Time Applications in Edge Computing Scenarios, IEEE Aerospace and Electronic Systems Magazine, vol. 34, no. 7, pp. 32–45, Jul. 2019.
  30. Garcı́a-Valls Marisol, A. Dubey, and V. J. Botti, Introducing the new paradigm of Social Dispersed Computing: Applications, Technologies and Challenges, Journal of Systems Architecture - Embedded Systems Design, vol. 91, pp. 83–102, 2018.
  31. S. Pradhan, A. Dubey, S. Khare, S. Nannapaneni, A. S. Gokhale, S. Mahadevan, D. C. Schmidt, and M. Lehofer, CHARIOT: Goal-Driven Orchestration Middleware for Resilient IoT Systems, TCPS, vol. 2, no. 3, pp. 16:1–16:37, 2018.
  32. S. Hasan, A. Ghafouri, A. Dubey, G. Karsai, and X. D. Koutsoukos, Vulnerability analysis of power systems based on cyber-attack and defense models, in 2018 IEEE Power & Energy Society Innovative Smart Grid Technologies Conference, ISGT 2018, Washington, DC, USA, February 19-22, 2018, 2018, pp. 1–5.
  33. C. Samal, A. Dubey, and L. J. Ratliff, Mobilytics- An Extensible, Modular and Resilient Mobility Platform, in 2018 IEEE International Conference on Smart Computing, SMARTCOMP 2018, Taormina, Sicily, Italy, June 18-20, 2018, 2018, pp. 356–361.
  34. H. Tu, Y. Du, H. Yu, S. Lukic, M. Metelko, P. Volgyesi, A. Dubey, and G. Karsai, A Hardware-in-the-Loop Real-Time Testbed for Microgrid Hierarchical Control, in 2018 IEEE Energy Conversion Congress and Exposition (ECCE), 2018, pp. 2053–2059.
  35. F. Sun, A. Dubey, C. Kulkarni, N. Mahadevan, and A. G. Luna, A data driven health monitoring approach to extending small sats mission, in Conference Proceedings, Annual Conference of The Prognostics And Health Management Society, 2018.
  36. S. Nannapaneni, S. Mahadevan, and A. Dubey, Real-Time Control of Cyber-Physical Manufacturing Process Under Uncertainty, in Proceedings of ASME 2018 13th International Manufacturing Science and Engineering Conference, 2018, vol. Volume 3: Manufacturing Equipment and Systems.
  37. Y. Du, H. Tu, S. Lukic, D. Lubkeman, A. Dubey, and G. Karsai, Resilient Information Architecture Platform for Smart Systems (RIAPS): Case Study for Distributed Apparent Power Control, in 2018 IEEE/PES Transmission and Distribution Conference and Exposition (T D), 2018, pp. 1–5.
  38. A. Chhokra, A. Dubey, N. Mahadevan, S. Hasan, and G. Karsai, Diagnosis in Cyber-Physical Systems with Fault Protection Assemblies, in Diagnosability, Security and Safety of Hybrid Dynamic and Cyber-Physical Systems, M. Sayed-Mouchaweh, Ed. Cham: Springer International Publishing, 2018, pp. 201–225.
  39. A. Chhokra, A. Dubey, N. Mahadevan, G. Karsai, D. Balasubramanian, and S. Hasan, Hierarchical Reasoning about Faults in Cyber-Physical Energy Systems using Temporal Causal Diagrams, International Journal of Prognostics and Health Management, vol. 9, no. 1, Feb. 2018.
  40. A. Laszka, A. Mavridou, and A. Dubey, Resilient and Trustworthy Transactive Platform for Smart and Connected Communities, in High Confidence Software and Systems Conference, 2018.
  41. A. Ghafouri, A. Laszka, A. Dubey, and X. D. Koutsoukos, Optimal detection of faulty traffic sensors used in route planning, in Proceedings of the 2nd International Workshop on Science of Smart City Operations and Platforms Engineering, SCOPE@CPSWeek 2017, Pittsburgh, PA, USA, April 21, 2017, 2017, pp. 1–6.
  42. A. Chhokra, A. Kulkarni, S. Hasan, A. Dubey, N. Mahadevan, and G. Karsai, A Systematic Approach of Identifying Optimal Load Control Actions for Arresting Cascading Failures in Power Systems, in Proceedings of the 2nd Workshop on Cyber-Physical Security and Resilience in Smart Grids, SPSR-SG@CPSWeek 2017, Pittsburgh, PA, USA, April 21, 2017, 2017, pp. 41–46.
  43. A. Dubey, G. Karsai, and S. Pradhan, Resilience at the edge in cyber-physical systems, in Second International Conference on Fog and Mobile Edge Computing, FMEC 2017, Valencia, Spain, May 8-11, 2017, 2017, pp. 139–146.
  44. S. Eisele, G. Pettet, A. Dubey, and G. Karsai, Towards an architecture for evaluating and analyzing decentralized Fog applications, in IEEE Fog World Congress, FWC 2017, Santa Clara, CA, USA, October 30 - Nov. 1, 2017, 2017, pp. 1–6.
  45. A. Chhokra, S. Hasan, A. Dubey, N. Mahadevan, and G. Karsai, Diagnostics and prognostics using temporal causal models for cyber physical energy systems, in Proceedings of the 8th International Conference on Cyber-Physical Systems, ICCPS 2017, Pittsburgh, Pennsylvania, USA, April 18-20, 2017, 2017, p. 87.
  46. S. Hasan, A. Chhokra, A. Dubey, N. Mahadevan, G. Karsai, R. Jain, and S. Lukic, A simulation testbed for cascade analysis, in IEEE Power & Energy Society Innovative Smart Grid Technologies Conference, ISGT 2017, Washington, DC, USA, April 23-26, 2017, 2017, pp. 1–5.
  47. S. Eisele, I. Madari, A. Dubey, and G. Karsai, RIAPS: Resilient Information Architecture Platform for Decentralized Smart Systems, in 20th IEEE International Symposium on Real-Time Distributed Computing, ISORC 2017, Toronto, ON, Canada, May 16-18, 2017, 2017, pp. 125–132.
  48. J. Bergquist, A. Laszka, M. Sturm, and A. Dubey, On the design of communication and transaction anonymity in blockchain-based transactive microgrids, in Proceedings of the 1st Workshop on Scalable and Resilient Infrastructures for Distributed Ledgers, SERIAL@Middleware 2017, Las Vegas, NV, USA, December 11-15, 2017, 2017, pp. 3:1–3:6.
  49. P. Völgyesi, A. Dubey, T. Krentz, I. Madari, M. Metelko, and G. Karsai, Time synchronization services for low-cost fog computing applications, in International Symposium on Rapid System Prototyping, RSP 2017, Shortening the Path from Specification to Prototype, October 19-20, 2017, Seoul, South Korea, 2017, pp. 57–63.
  50. S. Nannapaneni, A. Dubey, and S. Mahadevan, Performance evaluation of smart systems under uncertainty, in 2017 IEEE SmartWorld, 2017, pp. 1–8.
  51. A. Dubey, G. Karsai, A. Gokhale, W. Emfinger, and P. Kumar, Drems-os: An operating system for managed distributed real-time embedded systems, in 2017 6th International Conference on Space Mission Challenges for Information Technology (SMC-IT), 2017, pp. 114–119.
  52. S. Hasan, A. Ghafouri, A. Dubey, G. Karsai, and X. Koutsoukos, Heuristics-based approach for identifying critical N-k contingencies in power systems, in 2017 Resilience Week (RWS), 2017, pp. 191–197.
  53. S. Hasan, A. Dubey, A. Chhokra, N. Mahadevan, G. Karsai, and X. Koutsoukos, A modeling framework to integrate exogenous tools for identifying critical components in power systems, in 2017 Workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), 2017, pp. 1–6.
  54. S. Pradhan, A. Dubey, T. Levendovszky, P. S. Kumar, W. Emfinger, D. Balasubramanian, W. Otte, and G. Karsai, Achieving resilience in distributed software systems via self-reconfiguration, Journal of Systems and Software, vol. 122, pp. 344–363, 2016.
  55. G. Martins, A. Moondra, A. Dubey, A. Bhattacharjee, and X. D. Koutsoukos, Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems, Sensors, vol. 16, no. 8, p. 1166, 2016.
  56. S. Pradhan, A. Dubey, S. Khare, F. Sun, J. Sallai, A. S. Gokhale, D. C. Schmidt, M. Lehofer, and M. Sturm, Poster Abstract: A Distributed and Resilient Platform for City-Scale Smart Systems, in IEEE/ACM Symposium on Edge Computing, SEC 2016, Washington, DC, USA, October 27-28, 2016, 2016, pp. 99–100.
  57. W. Emfinger, A. Dubey, P. Völgyesi, J. Sallai, and G. Karsai, Demo Abstract: RIAPS - A Resilient Information Architecture Platform for Edge Computing, in IEEE/ACM Symposium on Edge Computing, SEC 2016, Washington, DC, USA, October 27-28, 2016, 2016, pp. 119–120.
  58. A. Chhokra, A. Dubey, N. Mahadevan, and G. Karsai, Poster Abstract: Distributed Reasoning for Diagnosing Cascading Outages in Cyber Physical Energy Systems, in 7th ACM/IEEE International Conference on Cyber-Physical Systems, ICCPS 2016, Vienna, Austria, April 11-14, 2016, 2016, p. 33:1.
  59. S. Pradhan, A. Dubey, and A. S. Gokhale, WiP Abstract: Platform for Designing and Managing Resilient and Extensible CPS, in 7th ACM/IEEE International Conference on Cyber-Physical Systems, ICCPS 2016, Vienna, Austria, April 11-14, 2016, 2016, p. 39:1.
  60. A. Dubey, S. Pradhan, D. C. Schmidt, S. Rusitschka, and M. Sturm, The Role of Context and Resilient Middleware in Next Generation Smart Grids, in Proceedings of the 3rd Workshop on Middleware for Context-Aware Applications in the IoT, M4IoT@Middleware 2016, Trento, Italy, December 12-13, 2016, 2016, pp. 1–6.
  61. S. Pradhan, A. Dubey, and A. S. Gokhale, Designing a Resilient Deployment and Reconfiguration Infrastructure for Remotely Managed Cyber-Physical Systems, in Software Engineering for Resilient Systems - 8th International Workshop, SERENE 2016, Gothenburg, Sweden, September 5-6, 2016, Proceedings, 2016, pp. 88–104.
  62. S. Nannapaneni, S. Mahadevan, S. Pradhan, and A. Dubey, Towards Reliability-Based Decision Making in Cyber-Physical Systems, in 2016 IEEE International Conference on Smart Computing, SMARTCOMP 2016, St Louis, MO, USA, May 18-20, 2016, 2016, pp. 1–6.
  63. H. Neema, W. Emfinger, and A. Dubey, A Reusable and Extensible Web-Based Co-Simulation Platform for Transactive Energy Systems, in Proceedings of the 3rd International Transactive Energy Systems, Portland, Oregon, USA, 2016, vol. 12.
  64. S. Pradhan, A. Dubey, S. Neema, and A. Gokhale, Towards a generic computation model for smart city platforms, in 2016 1st International Workshop on Science of Smart City Operations and Platforms Engineering (SCOPE) in partnership with Global City Teams Challenge (GCTC) (SCOPE - GCTC), 2016, pp. 1–6.
  65. N. Mahadevan, A. Dubey, A. Chhokra, H. Guo, and G. Karsai, Using temporal causal models to isolate failures in power system protection devices, IEEE Instrum. Meas. Mag., vol. 18, no. 4, pp. 28–39, 2015.
  66. D. Balasubramanian, A. Dubey, W. Otte, T. Levendovszky, A. S. Gokhale, P. S. Kumar, W. Emfinger, and G. Karsai, DREMS ML: A wide spectrum architecture design language for distributed computing platforms, Sci. Comput. Program., vol. 106, pp. 3–29, 2015.
  67. S. M. Pradhan, A. Dubey, A. S. Gokhale, and M. Lehofer, CHARIOT: a domain specific language for extensible cyber-physical systems, in Proceedings of the Workshop on Domain-Specific Modeling, DSM@SPLASH 2015, Pittsburgh, PA, USA, October 27, 2015, 2015, pp. 9–16.
  68. A. Chhokra, S. Abdelwahed, A. Dubey, S. Neema, and G. Karsai, From system modeling to formal verification, in 2015 Electronic System Level Synthesis Conference (ESLsyn), 2015, pp. 41–46.
  69. A. Chhokra, A. Dubey, N. Mahadevan, and G. Karsai, A component-based approach for modeling failure propagations in power systems, in 2015 Workshop on Modeling and Simulation of Cyber-Physical Energy Systems (MSCPES), 2015, pp. 1–6.
  70. T. Levendovszky, A. Dubey, W. Otte, D. Balasubramanian, A. Coglio, S. Nyako, W. Emfinger, P. S. Kumar, A. S. Gokhale, and G. Karsai, Distributed Real-Time Managed Systems: A Model-Driven Distributed Secure Information Architecture Platform for Managed Embedded Systems, IEEE Software, vol. 31, no. 2, pp. 62–69, 2014.
  71. W. Emfinger, G. Karsai, A. Dubey, and A. S. Gokhale, Analysis, verification, and management toolsuite for cyber-physical applications on time-varying networks, in Proceedings of the 4th ACM SIGBED International Workshop on Design, Modeling, and Evaluation of Cyber-Physical Systems, CyPhy 2014, Berlin, Germany, April 14-17, 2014, 2014, pp. 44–47.
  72. G. Karsai, D. Balasubramanian, A. Dubey, and W. Otte, Distributed and Managed: Research Challenges and Opportunities of the Next Generation Cyber-Physical Systems, in 17th IEEE International Symposium on Object/Component/Service-Oriented Real-Time Distributed Computing, ISORC 2014, Reno, NV, USA, June 10-12, 2014, 2014, pp. 1–8.
  73. D. Balasubramanian, T. Levendovszky, A. Dubey, and G. Karsai, Taming Multi-Paradigm Integration in a Software Architecture Description Language, in Proceedings of the 8th Workshop on Multi-Paradigm Modeling co-located with the 17th International Conference on Model Driven Engineering Languages and Systems, MPM@MODELS 2014, Valencia, Spain, September 30, 2014, 2014, pp. 67–76.
  74. P. S. Kumar, A. Dubey, and G. Karsai, Colored Petri Net-based Modeling and Formal Analysis of Component-based Applications, in Proceedings of the 11th Workshop on Model-Driven Engineering, Verification and Validation co-located with 17th International Conference on Model Driven Engineering Languages and Systems, MoDeVVa@MODELS 2014, Valencia, Spain, September 30, 2014, 2014, pp. 79–88.
  75. D. Balasubramanian, A. Dubey, W. R. Otte, W. Emfinger, P. S. Kumar, and G. Karsai, A Rapid Testing Framework for a Mobile Cloud, in 25nd IEEE International Symposium on Rapid System Prototyping, RSP 2014, New Delhi, India, October 16-17, 2014, 2014, pp. 128–134.
  76. N. Mahadevan, A. Dubey, G. Karsai, A. Srivastava, and C.-C. Liu, Temporal Causal Diagrams for diagnosing failures in cyber-physical systems, in Annual Conference of the Prognostics and Health Management Society, 2014.
  77. S. Pradhan, W. Emfinger, A. Dubey, W. R. Otte, D. Balasubramanian, A. Gokhale, G. Karsai, and A. Coglio, Establishing Secure Interactions across Distributed Applications in Satellite Clusters, in 2014 IEEE International Conference on Space Mission Challenges for Information Technology, 2014, pp. 67–74.
  78. S. Pradhan, W. Otte, A. Dubey, A. Gokhale, and G. Karsai, Key Considerations for a Resilient and Autonomous Deployment and Configuration Infrastructure for Cyber-Physical Systems, in Proceedings of the 11th IEEE International Conference and Workshops on the Engineering of Autonomic and Autonomous Systems (EASe’14), 2014.
  79. G. Martins, A. Bhattacharjee, A. Dubey, and X. D. Koutsoukos, Performance evaluation of an authentication mechanism in time-triggered networked control systems, in 2014 7th International Symposium on Resilient Control Systems (ISRCS), 2014, pp. 1–6.
  80. W. R. Otte, A. Dubey, and G. Karsai, A resilient and secure software platform and architecture for distributed spacecraft, in Sensors and Systems for Space Applications VII, 2014, vol. 9085, pp. 121–130.
  81. S. Nannapaneni, A. Dubey, S. Abdelwahed, S. Mahadevan, and S. Neema, A Model-Based Approach for Reliability Assessment in Component-Based Systems, in PHM 2014 - Proceedings of the Annual Conference of the Prognostics and Health Management Society 2014, 2014.
  82. S. Pradhan, W. Otte, A. Dubey, C. Szabo, A. Gokhale, and G. Karsai, Towards a Self-adaptive Deployment and Configuration Infrastructure for Cyber-Physical Systems, Institute for Software Integrated Systems, Vanderbilt University, Nashville, Technical Report ISIS-14-102, 2014.
  83. A. Dubey and G. Karsai, Software health management, Innovations in System and Software Engineering, vol. 9, no. 4, p. 217, 2013.
  84. N. Mahadevan, A. Dubey, D. Balasubramanian, and G. Karsai, Deliberative, search-based mitigation strategies for model-based software health management, ISSE, vol. 9, no. 4, pp. 293–318, 2013.
  85. S. Pradhan, W. Otte, A. Dubey, A. S. Gokhale, and G. Karsai, Towards a resilient deployment and configuration infrastructure for fractionated spacecraft, SIGBED Review, vol. 10, no. 4, pp. 29–32, 2013.
  86. W. Otte, A. Dubey, S. Pradhan, P. Patil, A. S. Gokhale, G. Karsai, and J. Willemsen, F6COM: A component model for resource-constrained and dynamic space-based computing environments, in 16th IEEE International Symposium on Object/Component/Service-Oriented Real-Time Distributed Computing, ISORC 2013, Paderborn, Germany, June 19-21, 2013, 2013, pp. 1–8.
  87. A. Dubey, G. Karsai, and N. Mahadevan, Fault-Adaptivity in Hard Real-Time Component-Based Software Systems, in Software Engineering for Self-Adaptive Systems II: International Seminar, Dagstuhl Castle, Germany, October 24-29, 2010 Revised Selected and Invited Papers, R. de Lemos, H. Giese, H. A. Müller, and M. Shaw, Eds. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013, pp. 294–323.
  88. A. Dubey, G. Karsai, N. Mahadevan, A. Srivastava, C. C. Liu, and S. Lukic, Understanding Failure Dynamics in the Smart Electric Grid, in NSF Energy Cyber Physical System Workshop, Washington DC, 2013.
  89. J. Shi, R. Amgai, S. Abdelwahed, A. Dubey, J. Humphreys, M. Alattar, and R. Jia, Generic modeling and analysis framework for shipboard system design, in 2013 IEEE Electric Ship Technologies Symposium (ESTS), 2013, pp. 420–428.
  90. W. Emfinger, P. Kumar, A. Dubey, W. Otte, A. Gokhale, and G. Karsai, Drems: A toolchain and platform for the rapid application development, integration, and deployment of managed distributed real-time embedded systems, in IEEE Real-time Systems Symposium, 2013.
  91. N. Mahadevan, A. Dubey, D. Balasubramanian, and G. Karsai, Deliberative Reasoning in Software Health Management, Institute for Software Integrated Systems, Vanderbilt University, techreport ISIS-13-101, 2013.
  92. N. Mahadevan, A. Dubey, and G. Karsai, Architecting Health Management into Software Component Assemblies: Lessons Learned from the ARINC-653 Component Mode, in 15th IEEE International Symposium on Object/Component/Service-Oriented Real-Time Distributed Computing, ISORC 2012, Shenzhen, China, April 11-13, 2012, 2012, pp. 79–86.
  93. A. Dabholkar, A. Dubey, A. S. Gokhale, G. Karsai, and N. Mahadevan, Reliable Distributed Real-Time and Embedded Systems through Safe Middleware Adaptation, in IEEE 31st Symposium on Reliable Distributed Systems, SRDS 2012, Irvine, CA, USA, October 8-11, 2012, 2012, pp. 362–371.
  94. R. Mehrotra, A. Dubey, S. Abdelwahed, and A. N. Tantawi, Power-Aware Modeling and Autonomic Management Framework for Distributed Computing Systems, in Handbook of Energy-Aware and Green Computing - Two Volume Set, CRC Press, 2012, pp. 621–648.
  95. A. Dubey, W. Emfinger, A. Gokhale, G. Karsai, W. R. Otte, J. Parsons, C. Szabo, A. Coglio, E. Smith, and P. Bose, A software platform for fractionated spacecraft, in 2012 IEEE Aerospace Conference, 2012, pp. 1–20.
  96. A. Dubey, N. Mahadevan, and G. Karsai, A deliberative reasoner for model-based software health management, in The Eighth International Conference on Autonomic and Autonomous Systems, 2012, pp. 86–92.
  97. R. Mehrotra, A. Dubey, S. Abdelwahed, and K. W. Rowland, RFDMon: A Real-time and Fault-tolerant Distributed System Monitoring Approach, in The 8th International Conference on Autonomic and Autonomous Systems ICAS 2012, 2012.
  98. A. Dubey, G. Karsai, and N. Mahadevan, Formalization of a Component Model for Real-time Systems, Institute for Software Integrated Systems, Vanderbilt University, ISIS-12-102, 2012.
  99. A. Dubey, N. Mahadevan, and G. Karsai, The Inertial Measurement Unit Example: A Software Health Management Case Study, Insitute for Software Integrated Systems, Vanderbilt University, ISIS-12-101, 2012.
  100. S. Nordstrom, A. Dubey, T. Keskinpala, S. Neema, and T. Bapty, Autonomic Healing of Model-Based Systems, JACIC, vol. 8, no. 4, pp. 87–99, 2011.
  101. A. Dubey, G. Karsai, and N. Mahadevan, A component model for hard real-time systems: CCM with ARINC-653, Softw., Pract. Exper., vol. 41, no. 12, pp. 1517–1550, 2011.
  102. N. Roy, A. Dubey, and A. S. Gokhale, Efficient Autoscaling in the Cloud Using Predictive Models for Workload Forecasting, in IEEE International Conference on Cloud Computing, CLOUD 2011, Washington, DC, USA, 4-9 July, 2011, 2011, pp. 500–507.
  103. N. Mahadevan, A. Dubey, and G. Karsai, Application of software health management techniques, in 2011 ICSE Symposium on Software Engineering for Adaptive and Self-Managing Systems, SEAMS 2011, Waikiki, Honolulu , HI, USA, May 23-24, 2011, 2011, pp. 1–10.
  104. N. Roy, A. Dubey, A. S. Gokhale, and L. W. Dowdy, A Capacity Planning Process for Performance Assurance of Component-based Distributed Systems, in ICPE’11 - Second Joint WOSP/SIPEW International Conference on Performance Engineering, Karlsruhe, Germany, March 14-16, 2011, 2011, pp. 259–270.
  105. S. Abdelwahed, A. Dubey, G. Karsai, and N. Mahadevan, Model-based Tools and Techniques for Real-Time System and Software Health Management, in Machine Learning and Knowledge Discovery for Engineering Systems Health Management, CRC Press, 2011, p. 285.
  106. R. Mehrotra, A. Dubey, S. Abdelwahed, and W. Monceaux, Large Scale Monitoring and Online Analysis in a Distributed Virtualized Environment, in 2011 Eighth IEEE International Conference and Workshops on Engineering of Autonomic and Autonomous Systems, 2011, pp. 1–9.
  107. A. Dubey, G. Karsai, and N. Mahadevan, Model-based software health management for real-time systems, in 2011 Aerospace Conference, 2011, pp. 1–18.
  108. R. Mehrotra, A. Dubey, J. Kwalkowski, M. Paterno, A. Singh, R. Herber, and S. Abdelwahed, RFDMon: A Real-Time and Fault-Tolerant Distributed System Monitoring Approach, Vanderbilt University, Nashville, 2011.
  109. N. Mahadevan, A. Dubey, and G. Karsai, A Case Study On The Application of Software Health Management Techniques, Institute For Software Integrated Systems, Vanderbilt University, Nashville, ISIS-11-101, 2011.
  110. A. Dubey, G. Karsai, R. Kereskényi, and N. Mahadevan, A Real-Time Component Framework: Experience with CCM and ARINC-653, in 13th IEEE International Symposium on Object/Component/Service-Oriented Real-Time Distributed Computing, ISORC 2010, Carmona, Sevilla, Spain, 5-6 May 2010, 2010, pp. 143–150.
  111. J. Balasubramanian, A. S. Gokhale, A. Dubey, F. Wolf, C. Lu, C. D. Gill, and D. C. Schmidt, Middleware for Resource-Aware Deployment and Configuration of Fault-Tolerant Real-time Systems, in 16th IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS 2010, Stockholm, Sweden, April 12-15, 2010, 2010, pp. 69–78.
  112. A. Dubey, R. Mehrotra, S. Abdelwahed, and A. N. Tantawi, Performance modeling of distributed multi-tier enterprise systems, SIGMETRICS Performance Evaluation Review, vol. 37, no. 2, pp. 9–11, 2009.
  113. A. Dubey, G. Karsai, and S. Abdelwahed, Compensating for Timing Jitter in Computing Systems with General-Purpose Operating Systems, in 2009 IEEE International Symposium on Object/Component/Service-Oriented Real-Time Distributed Computing, ISORC 2009, Tokyo, Japan, 17-20 March 2009, 2009, pp. 55–62.
  114. A. Dubey, S. Nordstrom, T. Keskinpala, S. Neema, T. Bapty, and G. Karsai, Towards a verifiable real-time, autonomic, fault mitigation framework for large scale real-time systems, ISSE, vol. 3, no. 1, pp. 33–52, 2007.
  115. A. Dubey, X. Wu, H. Su, and T. J. Koo, Computation Platform for Automatic Analysis of Embedded Software Systems Using Model Based Approach, in Automated Technology for Verification and Analysis, Berlin, Heidelberg, 2005, pp. 114–128.